Preparation And Characterization Of Anionic Polyamide-6 For Wind Turbine Blades

Polyamide-6(PA6) are commonly used engineering plastics in the automotive,household and textile industry because of their formidable mechanical properties,excellent resistance against abrasion and chemical,ease of processing and good price/performance ratio. Wind energy is well on its way of becoming one of our mainstream sources of energy. However, it is feared that soon the limit of the current blade technology is reached and that new and improved materials and more efficient blade designs are necessary to overcome what has truly become a technological challenge:manufacturing of large wind turbine blades. Since joining of thermoset composites through structural bonding or mechanical fastening is tedious, labor intensive and time consuming, the future blade manufacturing is focus on thermoplastic composites—Polyamide-6. Parts are manufactured from both the neat polymer as well as from polyamide-based composites with for instance a particle or fiber reinforcement. The most common way of producing PA-6 parts is through melt processing of hydrolytic polymerized caprolactam. The main drawback related to melt processing of thermoplastic composites is the limited size and thickness of the parts that can be obtained. The alternative method of reactive processing via anionic polymerization of caprolactam. Specifically for vacuum infusion process an activator-initiator combination is selected, which prolongs the initial dissociation and complex formation steps sufficiently to allow for long mould filling times. In the subsequent polymerization step the reaction rate increases again, which prevents confinement of reactive species and consequently results in a highly crystalline polymer with a high conversionHexano-6-lactam (e-caprolactam)-magnesium bromide (CLMgBr),a new effective initiator of the anionic polymerization of e-caprolactam, is synthesized at low temperature. The DSC shows only one endotherm centered at 169.4℃, which corresponds to the melting temperature. TGA record of the complex is stable up to 180℃,the decomposition ends with an ash content of about 5%,the molecular structure MgBr2-CL6 with almost exactly equivalent positions of all six lactam molecules is proposed. This paper describes the synthesis of PA-6 initiated with the sodium salt of e-caprolactam, hexamethylene-1,6-dicarbamoylcaprolactam or MgBr2-CL6 . It is found that MgBr2-CL6 prolongs the initial dissociation. The polymer of PA 6 monomer is studied by fourier transform infrared spectrometry(FTIR),XRD.The effect of processing parameters like temperature, demolding time on the physical and mechanical of the neat polymer is discussed. As is the case with all semi-crystalline polymers, the Young's modulus and the maximum strength increase with increasing degree of crystallinity. There is a little difference between 30min and 45min samples. The Young's modulus is 4.1GPa, the maximum strength is 86MPa.